- 二级市场 èrjíshìchǎng secondary marketA market where previously issued financial instruments, securities, or properties are traded between investors; also refers to a parallel market.
- 二级头 èrjítóu second stagethe second stage of a scuba regulator that reduces air pressure and provides it through a mouthpiece; used in diving
- 备用二级头呼吸器 bèiyòng'èrjítóuhūxīqì octopus(scuba diving) a backup regulator or secondary air source used for emergencies
- 第二级产业 dì'èrjíchǎnyè secondary industrythe sector of the economy concerned with manufacturing, construction, and processing of raw materials
- 二级头呼吸器 èrjítóuhūxīqì regulator; demand valve(scuba diving) second-stage regulator; a device that reduces air pressure to a breathable level upon inhalation
- 二级士官 èrjíshìguān Sergeant Second Classformer rank in the Chinese People's Liberation Army (1999-2009), above [[一级士官|一級士官|yi1 ji2 shi4 guan1]] and below [[三级士官|三級士官|san1 ji2 shi4 guan1]]